Weird Keyboard Problem:

I posted this to the hardware group but didn't get any response and
thought that someone on here might be able to help. I have a Dell
Dimension 8200 with XP, SP2 and a Microsoft ergonomic 4000 v1.0
keyboard. The problem is this; normally when I push the backspace key
or back arrow button or use the mouse to click backspace it works but
on some sites it just cycles and does nothing and I have to do it 2-3
times before it backspaces. I have tried going into Safe Mode with
Networking and also tried using the online keyboard and it does the
same thing. I even reinstalled my keyboard drivers thinking it somehow
got corrupted but it still does it. It's not a stuck key, otherwise
why would I be able to backspace on most sites but not all? As an
example, this site requires me to backspace at least 3 times:

http://www.imdb.com/search

It didn’t use to be like this and I’m wondering why it does it now? In
passing, I have turned off the Microsoft automatics updates on the
advise of others and I’m just wondering if this may have affected it?
I would appreciate any help.


Thanks,
Robert
.